1. Field of the Invention
The invention relates to current generators, and in particular to linear-in-dB current generators having a maximum gain with least gain error and variable gain amplifiers using the same.
2. Description of the Related Art
In communications systems, analog receivers vary the amount of gain according to the specific receiver operation and the strength of the received signal, to maintain a constant signal level. Variable-gain amplifiers are typically used to achieve this desired effect in the receiver. Because of the wide range of received signal strength, the variable gain amplifier must be able to vary its gain over a wide range. Linear-in-decibel variable gain amplifiers have become known to provide this desired level of gain control.
The problem with conventional linear-in-decibel variable gain amplifiers is that they are complex and suffer from accuracy and bandwidth limitations. Accordingly, a need remains for a simple yet accurate variable amplifier, linear in decibels.